One of the main building blocks for a successful NFL team is to find a guy that can protect the quarterback's blind side. With so much value placed on protecting a team's franchise guy, it can be hard to find the right kind of player to fill that left tackle role.

Fortunately for teams picking at the top of the 2014 NFL draft, there's three of those players: Auburn's Greg Robinson, Texas A&M's Jake Matthews and Michigan's Taylor Lewan.

After that big there, there's a bit of a drop off when it comes to pure tackles. However, for teams looking for help on the interior of the offensive line, there's plenty to find in the first couple of rounds, whether it's Notre Dame's Zack Martin (also an option at tackle) or UCLA's Xavier Su'a Filo.

Let's take a look at this year's crop of offensive linemen:

1. OT Greg Robinson, Auburn

A redshirt sophomore in 2013, Robinson came from obscurity to the most dominant offensive lineman in college football over the course of a couple months. It was a fast rise. But after dominating elite competition down the stretch like he did in Auburn's run to the national title game, his NFL potential isn't unquestioned.

Projection: Top 5

Best fit: St. Louis Rams, No. 2 overall

2. OT Jake Matthews, Texas A&M

Matthews doesn't have the unlimited potential of Robinson, but is likely more NFL-ready right now. A pure technician, Matthews was ready to be a Top 10 pick last season. This year, he's still a top prospect that would have been a Top 5 lock had it not been for Robinson's dominant run.

Projection: Top 10

Best fit: Atlanta Falcons, No. 6 overall

3. OT Taylor Lewan, Michigan

Like Matthews, Lewan is another guy that could have come off the board early had he declared in 2013. Lewan's stock dropped a little bit, but he's shown teams plenty to prove that he can hold his own against top-level NFL rushers.

Depending on what team drafts him, Martin could either be a very good tackle, or one of the best guards in the league. Martin has some issues in holding the edge against some outside rushers. But inside at guard, Martin has no major holes in his game.

A former left tackle, Su'a Filo is a more dynamic prospect than you'll see from most guards. The former Bruin is athletic, powerful and is consistent in pass protection, although he has some concerns in blitz pickup.

I'm much higher on Yankey than most scouts. I love the power mean streak he brings to the guard position. There are some criticisms over his footwork and how he holds up against defenders getting leverage late in the rush. He could be dominant, or exploitable.

A late riser, Bitonio has been spotted in the first round of some mock drafts. That's pushing it a bit far for a guy that was barely a Day 2 pick a couple months ago. Still Bitonio shows great technique and agility. He was a left tackle at Nevada, but is almost guaranteed to move inside in the NFL.

Projection: Round 2-3

8. OT Morgan Moses, Virginia

A big, powerful, surprisingly mobile blocker, Moses could eventually be added to the list of franchise tackles to come out of this draft. However, he's a bit raw, and has some work to do in his footwork and technique.

Projection: Round 2

9. OT Cyrus Kouandijo, Alabama

The pre-draft process has been kind to most top linemen, except for Kouandijo. The Alabama product has been picked apart from many due to his inconsistent effort and explosion off the ball. He's another guy with the tools, but not the mindset.